1. Field of the Invention
The field of the invention is data processing, or, more specifically, Dual In-line Memory Module (‘DIMM’) riser cards, computer systems configured with DIMM riser cards, and methods of manufacturing DIMM riser cards.
2. Description of Related Art
The development of the EDVAC computer system of 1948 is often cited as the beginning of the computer era. Since that time, computer systems have evolved into extremely complicated devices. Today's computers are much more sophisticated than early systems such as the EDVAC. Computer systems typically include a combination of hardware and software components, application programs, operating systems, processors, buses, memory, input/output devices, and so on. As advances in semiconductor processing and computer architecture push the performance of the computer higher and higher, more sophisticated computer software has evolved to take advantage of the higher performance of the hardware, resulting in computer systems today that are much more powerful than just a few years ago.
Computer systems today increasingly require a greater amount of computer memory to operate. DIMM riser cards are utilized to extend the memory bus of a computer and increase the number of memory chips which may be installed in a computer mother board DIMM socket, without re-designing the mother board. Current DIMM riser cards have several drawbacks however. First, current DIMM riser cards have a large effective width prohibiting many mother boards from utilizing the riser cards. Specifically, DIMM sockets on a typical motherboard are placed near one other at a distance that less than the effective width of a riser card. As such, in many computer systems two riser cards cannot typically be placed in adjacent DIMM sockets, limiting the usefulness of such riser cards. Further, the current DIMM riser cards typically have substantially long electrical traces between upstream and downstream sockets on the card. When the downstream socket is empty—containing no DIMM—the traces act as stub antennae and introduce stub effect into electrical signals transmitted along the memory bus.